Most common causes of itching in pregnancy

Pruritic urticarial papules and plaques of pregnancy (PUPPP) is the most common dermatologic condition of pregnancy. It is more common in nulliparous women and occurs most often in the second and third trimesters of pregnancy. PUPPP is characterized by erythematous papules and plaques that are intensely pruritic and appear first on the abdomen. The lesions then commonly spread to the buttocks, thighs, and extremities with sparing of the face. Herpes gestationis is a blistering skin eruption that occurs more commonly in multiparous patients in the second or third trimester of pregnancy. The presence of vesicles and bullae help differentiate this skin condition from PUPPP.

Prurigo gestationis is a very rare dermatosis of pregnancy that is characterized by small, pruritic excoriated lesions that occur between 25 and 30 weeks. The lesions first appear on the trunk and forearms and can spread throughout the body as well. In cases of intrahepatic cholestasis of pregnancy, bile acids are cleared incompletely and accumulate in the dermis, which causes intense itching. These patients develop pruritus in late pregnancy; there are no characteristic skin changes or rashes except in women who develop excoriations from scratching.

Impetigo herpetiformis is a rare pustular eruption that forms along the margins of erythematous patches. This skin condition usually occurs in late pregnancy. The skin lesions usually begin at points of flexure and extend peripherally; mucous membranes are commonly involved. Patients with impetigo herpetiformis usually do not have intense pruritus, but more commonly have systemic symptoms of nausea, vomiting, diarrhea, chills, and fever.

HELLP syndrome Typical signs of pre-eclampsia is seen beforehand, including hypertension, thrombocytopenia and proteinuria. Around 20% will not have hypertension; however, thrombocytopenia will distinguish from intrahepatic cholestasis of pregnancy (ICP). Thrombocytopenia, transferases between 50 to 2000 units/L can be used to differentiate between other diseases. Renal impairment may also be present.

Acute fatty liver of pregnancy Pregnant women that look ill, frequently with malaise, nausea, many with typical signs of pre-eclampsia, coagulopathy and renal impairment are considered for this cause. Hypertension present in over 70% of cases. Transferases less than 1000 units/L, hypoglycaemia in most, elevated prothrombin time, elevated creatinine and proteinuria are the diagnostic points. CT/MRI of liver showing fatty infiltration makes the diagnosis more considerable. Liver biopsy can also be done sometimes to reassure and confirm the clinical diagnosis; nonetheless this is the most accurate means of diagnosis in most of the liver diseases.

Burhan Ahmed is currently Editor-in-Chief at Medicalopedia.org. He completed his residency from Michigan State University in 2015. He has written three short revision books on Biology, Stomatology and Gynecology, has 4 publications to his name. He is pursuing career in cosmetic dermatology.